Electric soldering-iron.



W. F. HOSFORD.

ELECTRIC SOLUERING IRON.

APPLICATION FILED AIIG.29. 191e.

Patented Nov. 27, 191% I?? Vevr Milla??? FIJOS/0rd Sti UNITED STATES PATENT OFFICE.

WILLIAM F. HOSFORD, OF OAK PARK, ILLINOIS, ASSIGNOR TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

ELECTRIC SOLDERING-IRON.

Specification of Letters Patent.

Patented Nov. 2'?, 1917.

Application led August 29, 1916 l Serial No. 117,421.

To all whom 'it may concern:

Be it known that I, VILLIAM F. Hosronn, a citizen of the United States, residing at Oak Park, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Electric Solder-ing- Irons, of which the following is a full, clear,

concise, and exact description.

This invention relates to electric soldering irons, and more particularly to an electric soldering iron in which the electric heating element is cored out to receive a noneven with the very best of construction these strains periodically break the conductor which necessitates the discontinuance of theiron until the heating element has been either repaired or replaced. It is the object of this invention to eliminate one of these strains by covering the metallic heat conducting core placed within the 'heating unit with a non-oxidizing coating. When the.

heat conducting core is made of copper or any other satisfactory dizing metal, layers of metallic oxid gradually pile up on the surface of the core and very soon the diameter of the core increases sufficiently to strain the heating element to the breaking point. By the use of a nonoxidizing core the life of the heating unit is materially increased.

In the preferred form of this invention, a core having a surface coating of aluminum bronze, or a solid aluminum bronze core is used. Soldering irons litted with cores'` of this kind have been in use for approximately one quarter of a year without any measurable increase in .the diameter of the core, whereas copper cores under the same conditions et service will increase substantially e of an inch in diameter in the same period.

The invention is illustrated in the accompanying drawings in which:

- Figure 1 is an elevation of the soldering iron partly in section;

Fig. 2 is an enlarged sectional elevation et the conductor carrying parts;

Fig. 3 is an enlarged elevation of the heatheat conducting, oxiing unit and its associated conductor carrying insulator, and

Fig. 4 is a section on the line 4-4 of Fig. 1.

The heating unit of the soldering iron consists of a current conducting, heat producing resistor, preferably in the form of a wire 4 which is wound into a helix, as illustrated in Fig. 4. This helically constructed wire is embedded in -a hollow cylinder 5 constructed of a suitable refractory insulating material, preferably alundum cement, as illustrated in Fig. 1. The cylinder 5 is inclosed in a cast iron shell 6 having a tapered end 7, the internal surface of which is threaded to receive the copper soldering tip 8 and the aluminum bronze heating core 9. The inner surface o the other end of the shell (3 is threaded to receive the metallic cap 11. Secured to the metallic cap 11 is the nut 12 which serves to interconnect the shell 6 and the metallic stem 14, to the other end of which is secured the wooden handle 15. Inclosed within the stem 14 and extending through the shell 11 so that it contacts with the cylinder 5 is a lavite insulator vtube 16. This lavite tube is itted with two longitudinally extending holes 17 and 18, through which the terminal leads from the resistor wire 4 extend. Fitted within the tube 14 and extending into the wooden handle 15 is the asbestos insulator tube 20. This tube is likewise fitted with a pair of longitudinally extending holes 21 and 22 which are in alinement with the holes 17 and 18 of the lavite tube 16. The asbestos tube is provided near its upper end with a pair of oppositely disposed slots 24 and 25 through which the holes 21 and 22 extend.

'As illustrated in Figs. 1 and 2, the external current supplying conductors for the iron are fitted into the opening in the top part of the wooden handle and arel then guided through the holes 21 and 22 to the slots 24 and 25. The connecting terminals from the resistor wire 4 are fed through the holes 17 and 18 and the lavite tube 16 from where they are threaded through the holes 21 and 22 through the asbestos tube 20 to the slots 24 and 25. The external current supply-` ing conductors 27 and 28 are soldered to the lresistor leads 29 and 30 in the slots 24 and 25. This soldered connection serves as a ready means for disconnecting the heating unit of the iron from the external current supplying conductors Whenever it is desired to repair or replace the heating unit. In soldering the resistor leads 29 and 30 to the external current supplying conductors 27 and 28 the cavities 24 and 25 are completely lled With solder so that any strain on the supply cord 31 will be absorbed by the solder in these slots and Will not be transmitted to the resistor leads 29 and 30.

In assembling the iron the aluminum bronze core 9 is first placed in position in the shell 6 after which the cylinder 5, Which is cored out to receive the aluminum bronze heat conductor 9, is put into position in the shell over the core 9 about which it is loosely fitted. The soldering tip 8 is then screwed into the end of the shell 6 until its end face butts up against the end face of the aluminum bronze core 9. The inclosing cap 11 is next placed on the shell 6 and the resistor terminal leads are then threaded through the laviteand asbestos tubes 16 and 2O respec-y tively, after which the stem l-l is placed over these tubes. The external current conducting leads are next fed through the handle 15 and through the holes 21 and 22 in the asbestos tube 20 and the leads 27 and 28 are then soldered to the resistor leads 29 and 30, after which the handle 15 is placed in position and locked by any suitable means, such as the slotted thread and lock nut 38 shown 'in Fig. 1.

It will be evident since the heat conducting core 9 is non-oxidizing that a very close fit between the surface of the heat conducting core 9 and the inner surface of the hollow cylinder 5 is permissible. This will result in excellent heat conduction from the heating resistor 4: to the soldering tip 8. Further, since the heat conducting core is non-oxidizing and as the resistor Wire 4 is completely embedded in the cylinder of refractory material 5, which tends to protect it from the air, none of the elements of the heating unit will be subject to any material oxidizing action. This is very beneficial and tends to greatly prolong the life of the iron.

Although the preferred form of this invention has been illustrated and described in connection with soldering irons, it Will be evident that the invention is as readily applicable to electrically heated branding, cauterizing, and numerous other tools and consequently that it is capable of many applications and variations Without departing from its spirit and scope.

What is claimed is:

1. A heating unit for an electric soldering device comprising in combination, an aluminum bronze heat conducting means andv an electrical heating unit embedded in a refractory insulating material cored to receive said means.

2. A heating unit for an electrical soldering iron comprising in combination, an electrical heating means embedded in a refractory insulating material which comprises a unitary removable unit and a metallic, nonoxidizing, heat conductin means projecting into and inclosed by said removable unit.

3. A heating unit for an electrical soldering iron comprising in combination, an electrical current conducting, heat producing means, a refractory positioning means in which said heat producing means is embedded, and a non-oxidizing, heat conducting, core removably fitted into said refractory positioning means.

4. A heating unit for an electrical soldering iron comprising in combination, an electrical current conducting, heat producing means, a refractory positioning means in which said heat producing means is embedded, and an aluminum bronze heat conducting core removably fitted into said refractory positioning means.

5. A heating unit for an electrical soldering iron comprising in combination, an electrical heating element, a heat conducting core contained Within said element. said core having an exterior surface of aluminum bronze whereby oxidization is prevented.

6. An electrical soldering iron comprising in combination, an electrical heat conducting means, a refractory positioning means in which said heat conducting means is embedded, an inclosing means for said positioning means, a soldering tip, and an aluminum bronze heat conducting core, said tip and said core being removably fitted end to end in said inclosing meansand said core fitting into an axial cavity in said positioning means.

t7. An electrical soldering iron comprising in combination, an electrical heating unit, an aluminum bronze heat conducting means which constitutes a core for said heating unit, a soldering tip, and an inclosing means for said heating unit in which said tip and core are mounted end to end.

8. An electrical soldering iron comprising in combination, a soldering tip, an aluminum bronze heat conducting means, a metallic housing in which said means and tip are fitted end to end, an electrical heating unit comprising an electrical heat `producing means embedded in a refractory insulating positioning means, said heating unit being removably fitted into said housing and about said heat conducting means as a core.

In Witness whereof, I hereunto subscribe my name this 21st da of August A. D.. 1916.

WILLIyAM F. HOSFORD. 

